FIELD OF THE INVENTION
The invention relates to a unit for controlling valves (a valve control unit) that are actuated by electromagnets, for a pressure fluid, including a housing having a housing frame and a lid, at least one valve coil disposed in the housing along with its components, such as a wound coil body and a yoke ring, and a circuit carrier being disposed in the interior of the housing and being electrically connected to each valve coil.
Such a valve control unit is an electronic control unit for an anti-lock brake system (ABS) in a motor vehicle, for instance, in which brake fluid actuating wheel brakes is controlled with two valves per wheel. The valves are each actuated by one electromagnet.
The invention also relates to a method for producing such a valve control unit.
An ABS system known from Published European Application No. 0 499 670 A1 has a housing with a housing frame and a lid. Valve coils are resiliently embedded in the housing frame. That is achieved by positioning the valve coils in their location with respect to the housing frame and filling interstices with a potting composition.
The components of the valve coil, such as the wound coil body and the yoke ring surrounding it, are filled with a potting composition before being installed in the housing frame. Next, the valve coils are installed in the housing and fixed by potting. Accordingly, in the valve control unit, two operations that are done separately from one another are needed in order to pot all of the parts. Problematic boundary layers or joint areas are created between the two potting compositions.